DaveG55

Since you've already screwed the lsn in so far you will probably have to unscrew it quite a ways to get it out far enough to clear the slide. You'll have to do this before you can reset the lsn.
To reset the lsn you have to do a few things. First you need to back out the idle screw (the angled one on top) so that you can completely close the carb slide. Next, hold the carb slide shut with one hand while gently screwing the lsn in until it bottoms out then back it out the reccomended number of turns. If you don't hold the carb closed then all you do is open the carb slide with the lsn. And finally reset the idle screw until you have a 1.5mm to 2mm opening.
Now, reset the hsn to factory settings and you'll be ready to tune the engine.
When tuning it's very important to make a short high speed run before you start tuning and between every needle adjustment. When tuning the lsn you need to let the truck idle for 5-10 seconds before you do the high speed run.
To tune the engine, start with the hsn. Tune it in 1/8 turn increments until you quit getting performance improvements then back the hsn back out 1/8 turn.
Now tune the lsn by turning the lsn in 1/16 turn increments until you quit getting performance improvements then back it out 1/16 turn.
Finally, adjust the idle needle until the truck will run but not try to move forward.
Tuning can be frustrating but once you learn it's not really all that dificult.
Keep in mind that any hobby has a learning curve. If it were too easy it would not be as much fun and that goes for ANY hobby.